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@@ -120,145 +120,3 @@ Retrieving all field instances of a model
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<django.db.models.fields.DateTimeField: date_joined>,
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<django.db.models.fields.related.ManyToManyField: groups>,
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<django.db.models.fields.related.ManyToManyField: user_permissions>)
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-
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-.. _migrating-old-meta-api:
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-
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-Migrating from the old API
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-==========================
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-
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-As part of the formalization of the ``Model._meta`` API (from the
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-:class:`django.db.models.options.Options` class), a number of methods and
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-properties have been deprecated and will be removed in Django 1.10.
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-
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-These old APIs can be replicated by either:
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-
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-* invoking :meth:`Options.get_field()
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- <django.db.models.options.Options.get_field()>`, or;
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-
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-* invoking :meth:`Options.get_fields()
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- <django.db.models.options.Options.get_fields()>` to retrieve a list of all
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- fields, and then filtering this list using the :ref:`field attributes
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- <model-field-attributes>` that describe (or retrieve, in the case of
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- ``_with_model`` variants) the properties of the desired fields.
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-
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-Although it's possible to make strictly equivalent replacements of the old
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-methods, that might not be the best approach. Taking the time to refactor any
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-field loops to make better use of the new API - and possibly include fields
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-that were previously excluded - will almost certainly result in better code.
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-
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-Assuming you have a model named ``MyModel``, the following substitutions
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-can be made to convert your code to the new API:
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-
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-* ``MyModel._meta.get_field(name)`` becomes::
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-
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- f = MyModel._meta.get_field(name)
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-
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- then check if:
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-
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- - ``f.auto_created == False``, because the new ``get_field()``
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- API will find "reverse" relations, and:
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-
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- - ``f.is_relation and f.related_model is None``, because the new
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- ``get_field()`` API will find
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- :class:`~django.contrib.contenttypes.fields.GenericForeignKey` relations.
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-
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-* ``MyModel._meta.get_field_by_name(name)`` returns a tuple of these four
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- values with the following replacements:
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-
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- - ``field`` can be found by ``MyModel._meta.get_field(name)``
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-
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- - ``model`` can be found through the
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- :attr:`~django.db.models.Field.model` attribute on the field.
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-
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- - ``direct`` can be found by: ``not field.auto_created or field.concrete``
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-
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- The :attr:`~django.db.models.Field.auto_created` check excludes
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- all "forward" and "reverse" relations that are created by Django, but
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- this also includes ``AutoField`` and ``OneToOneField`` on proxy models.
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- We avoid filtering out these attributes using the
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- :attr:`concrete <django.db.models.Field.concrete>` attribute.
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-
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- - ``m2m`` can be found through the
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- :attr:`~django.db.models.Field.many_to_many` attribute on the field.
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-
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-* ``MyModel._meta.get_fields_with_model()`` becomes::
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-
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- [
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- (f, f.model if f.model != MyModel else None)
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- for f in MyModel._meta.get_fields()
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- if not f.is_relation
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- or f.one_to_one
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- or (f.many_to_one and f.related_model)
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- ]
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-
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-* ``MyModel._meta.get_concrete_fields_with_model()`` becomes::
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-
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- [
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- (f, f.model if f.model != MyModel else None)
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- for f in MyModel._meta.get_fields()
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- if f.concrete and (
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- not f.is_relation
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- or f.one_to_one
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- or (f.many_to_one and f.related_model)
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- )
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- ]
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-
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-* ``MyModel._meta.get_m2m_with_model()`` becomes::
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-
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- [
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- (f, f.model if f.model != MyModel else None)
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- for f in MyModel._meta.get_fields()
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- if f.many_to_many and not f.auto_created
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- ]
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-
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-* ``MyModel._meta.get_all_related_objects()`` becomes::
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-
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- [
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- f for f in MyModel._meta.get_fields()
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- if (f.one_to_many or f.one_to_one)
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- and f.auto_created and not f.concrete
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- ]
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-
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-* ``MyModel._meta.get_all_related_objects_with_model()`` becomes::
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-
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- [
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- (f, f.model if f.model != MyModel else None)
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- for f in MyModel._meta.get_fields()
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- if (f.one_to_many or f.one_to_one)
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- and f.auto_created and not f.concrete
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- ]
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-
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-* ``MyModel._meta.get_all_related_many_to_many_objects()`` becomes::
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-
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- [
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- f for f in MyModel._meta.get_fields(include_hidden=True)
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- if f.many_to_many and f.auto_created
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- ]
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-
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-* ``MyModel._meta.get_all_related_m2m_objects_with_model()`` becomes::
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-
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- [
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- (f, f.model if f.model != MyModel else None)
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- for f in MyModel._meta.get_fields(include_hidden=True)
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- if f.many_to_many and f.auto_created
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- ]
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-
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-* ``MyModel._meta.get_all_field_names()`` becomes::
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-
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- from itertools import chain
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- list(set(chain.from_iterable(
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- (field.name, field.attname) if hasattr(field, 'attname') else (field.name,)
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- for field in MyModel._meta.get_fields()
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- # For complete backwards compatibility, you may want to exclude
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- # GenericForeignKey from the results.
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- if not (field.many_to_one and field.related_model is None)
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- )))
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-
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- This provides a 100% backwards compatible replacement, ensuring that both
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- field names and attribute names ``ForeignKey``\s are included, but fields
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- associated with ``GenericForeignKey``\s are not. A simpler version would be::
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-
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- [f.name for f in MyModel._meta.get_fields()]
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-
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- While this isn't 100% backwards compatible, it may be sufficient in many
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- situations.
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Tim Graham